Introduction to Cutaneous Biology

Human skin is the largest organ of the body. Together with various other components such as glands, fingernails, and hair, it comprises a complex system known as the integumentary system. Human skin performs a number of diverse functions critical to normal human health, including protection from environmental insults such as pathogens, physical damage, and radiation from the sun.

In addition, skin helps maintain homeostasis, possesses metabolic activity, delivers touch, heat, and pain sensations via the peripheral nervous system, excretes salts and wastes, and aids in wound healing. Primary skin cells are used in a variety of research and clinical applications:

Basic dermal biology

Wound healing and burn therapies

Malignant melanoma research

Toxicology studies

Epidermal model construction

Transdermal drug administration

Pigmentation and related disorders

Components of Skin

Skin is composed of the dermis and epidermis - each with unique components and functions. Contained within each layer are mixtures of cells and connective tissue that provide form and function for the skin (Figure 1). More specifically, keratinocytes, which produce keratin to harden and waterproof the skin, can be found in the epidermal layer. Melanocytes, which produce melanin, provide pigmentation for both hair and skin, deliver protection from UV radiation, and are found in fewer numbers in the dermal layer. Melanocytes intercalate up into the epidermis and establish close and critical interactions with keratinocytes to perform various cellular functions during development and normal maintenance of the skin.

Healthy skin also contains a number of other structural elements, including collagen fibers and fibroblasts located in the basement membrane, lending strength and structure to the skin. Layered within the basement membrane matrix are dermal microvasculature and lymphatic vessels for blood circulation and waste removal, vital to proper skin function.

Applications for Cutaneous Cell Systems

Research applications for cutaneous cell systems are shown in Table 1.

* The cells listed in Table 2 are also available as proliferating cultures available in their respective sections. All cells have tested negative for HIV-1, hepatitis B, hepatitis C, mycoplasmas, bacteria, yeast, and other fungi and are highly characterized.